Obi Rope 3 for Unity: what’s new

Obi Rope 3.0 is compatible with Obi Cloth 3 and Obi Fluid 3. It inherits all the improvements made to the core solver as part of the 3.x development cycle. But more importantly, it introduces a lot of rope-specific features that have been highly demanded.




Here we’ll outline some of the most important additions to Obi Rope 3.0:

Procedural geometry smoothing

Back in Obi Rope 1.x, procedural rope geometry was generated by directly using the particle representation of the rope. Because of this, ropes made of few particles had a very polygonal look:

To increase the smoothness of the geometry, you had to increase the amount of particles in the rope. However this has a negative impact on performance and convergence speed, leaving you between a rock and a hard place. In 3.0 we introduce a fast, non-recursive curve smoothing algorithm that can tesselate the geometry while keeping the same particle resolution:

This allows for extremely smooth-looking ropes that are also very fast to simulate and render.

Breakable ropes

Ropes can now be teared based on a per-particle tension threshold. Also, any prefab can be instantiated at the cut sites. Rendering torn fibers or spawning particles from ripped off wires can be done just by dragging a prefab to the rope inspector.

Dynamic resizing

In 1.x the only way to change rope length at runtime was to change the length of the distance constraints holding particles together. This of course kept the particle resolution constant, opening gaps in the rope and altering its behaviour.

In 3.0, new particles and constraints can be dynamically added at any point of the rope -even in the middle-, in any direction. All thanks to the new ObiRopeCursor component.

And yes, this works with tearable ropes too:

Stitch constraints

You can now stitch together separate ropes to create t-junctions, nets, and all kinds of multi-rope setups:


With this release, all our Obi products now sit in the 3.x framework and we are ready to move on to more new and exciting features. 🙂


Visit our official website for Obi to find more information.

The VM team


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